The project to build a giant skyscraper next to New York City's "Ground Zero", and a massive train and subway station underneath, will be delayed and run about $1bn over budget, a report from the government agency in charge of the site said yesterday.

The Freedom Tower, the signature building on the site designed to be one of the tallest in North America on its completion, is planned to be built by the end of 2013 - at least four years later than the earliest mooted date -- and for $3.1bn (£1.75bn), which is $200m more than previously estimated, the Port Authority of New York and New Jersey said.